1. Field of the Invention
The present invention relates to an assembly process apparatus with which it is possible to change the equipment capacity of line equipment in correspondence with fluctuations of production volume of a product.
2. Description of Related Art
Conventionally, an assembly processed product is manufactured by a series of line equipments which successively assemble numerous steps consecutively.
That is, as shown in FIG. 14, as the above-mentioned assembly process apparatus 9, for example, there is one consisting of ten assembly robots 91 disposed along a belt conveyor 95. The assembly robots 91 each have a tool 93 as an assembly process module corresponding to a step to be carried out.
The assembly robots 91 each grasp a part 6 with the tool 93 and assemble the part 6 to a workpiece 2 carried thereto on the belt conveyor 95. Then, the belt conveyor 95 carries the workpiece 2 with the part 6 assembled thereto to in front of the assembly robot 91 which will carry out the next step.
In this way, in the series of line equipments, successively, assembly and carrying are repeated, and when the assembly of the tenth assembly robot 91, which carries out a final step, finishes, one unit of a product 29 is completed.
The assembly process apparatus 9 described above, by carrying out a series of operations like this, provides a predetermined production volume.
However, in the conventional assembly process apparatus 9 described above, there are the following problems.
That is, the assembly process apparatus 9, by the time it completes the product 29, necessitates all of the above-mentioned ten assembly robots 91. Consequently, even when the production volume has decreased, the series of operations must be carried out using all of the ten assembly robots 91.
That is, in the assembly process apparatus 9, irrespective of the size of the production volume, to manufacture one product 29, all of the ten assembly robots 91 are necessary, and the equipments necessary for the manufacture of that product 29 are fixed.
On the other hand, in recent years, often the demand volume of a product is not constant, and fluctuates with for example model changes of the product.
Consequently, when the production volume is large, because the assembly process apparatus 9 is fully active, production efficiency is high. However, when the production volume decreases, the production efficiency falls, and the period for which the whole assembly process apparatus 9 is in an idle state becomes long. In this case, the operating efficiency of the assembly process apparatus 9 is low and consequently the production cost becomes high.